| Number of patients with ILI with samples that tested positive for influenza viruses during 2008 (numerator) |
15 |
22 |
38 |
18 |
93 |
| Census population in catchment area in 2008 (denominator) |
407 276 |
680 113 |
513 894 |
770 318 |
2 371 601 |
| Sampling fraction (i.e. surveillance 2 days per month) (denominator) |
0.07 |
0.07 |
0.07 |
0.07 |
0.07 |
| Patients with ILI who sought care at sentinel site during past 2 months (divided by 8 to extrapolate to 7 days)/Number with ILI during 7 days (denominator) |
4/687 |
2/528 |
7/624 |
1/596 |
14/2435 |
Incidence of influenza-associated ILI (per 100 person–years) during 2008
|
10
|
13
|
10
|
21
|
10
|
|
| Number of patients with ILI whose samples tested positive for influenza viruses during 2009 (numerator) |
23 |
41 |
33 |
18 |
115 |
| Census population in catchment area during 2009 (denominator) |
413 386 |
690 315 |
521 602 |
781 873 |
2 407 175 |
| Sampling fraction (i.e. surveillance 2 days per month) (denominator) |
0.07 |
0.07 |
0.07 |
0.07 |
0.07 |
| Number of patients with ILI who sought care at sentinel site during past 2 months (divided by 8 to extrapolate to 7 days)/Number with ILI during 7 days (denominator) |
4/687 |
2/528 |
7/624 |
1/596 |
14/2435 |
Incidence of influenza-associated ILI (per 100 person–years) during 2009
|
15
|
24
|
9
|
21
|
13
|
|
| Number of patients with ILI whose samples tested positive for influenza during 2010 (numerator) |
26 |
55 |
46 |
31 |
158 |
| Census population in catchment area in 2009 (denominator) |
419 586 |
700 669 |
529 426 |
793 601 |
2 443 283 |
| Sampling fraction (i.e. surveillance 2 days per month) (denominator) |
0.07 |
0.07 |
0.07 |
0.07 |
0.07 |
| Number of patients with ILI who sought care at sentinel site during past 2 months (divided by 8 to extrapolate to 7 days)/Number with ILI during 7 days (denominator) |
4/687 |
2/528 |
7/624 |
1/596 |
14/2435 |
| Incidence of influenza-associated ILI (per 100 person–years) in 2010
|
16 |
32 |
35 |
35 |
17 |
